staging: rtl8192e: fix wrong assignment

This patch addresses a spatch warning on assigning a negative
value to a unsigned integer.Similar patch has been submitted by
Larry Finger earlier to silence the same spatch warning in another
file.
Signed-off-by: Hari Prasath Gujulan Elango <hgujulan@visteon.com>
Acked-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8192e/rtl8192e/rtl_core.c

@@ -2311,7 +2311,7 @@ static void rtl8192_rx_normal(struct net_device *dev)
 
 	struct rtllib_rx_stats stats = {
 		.signal = 0,
-		.noise = -98,
+		.noise = (u8) -98,
 		.rate = 0,
 		.freq = RTLLIB_24GHZ_BAND,
 	};